Method and apparatus for controlling sidelink qos

ABSTRACT

The present application generally relates to wireless communication technology. More particularly, it relates to a method and apparatus for controlling sidelink (SL) Quality of Service (QoS). According to one or more embodiments, a method for controlling sidelink (SL) Quality of Service (QoS) comprising the following steps carried out at a User Equipment (UE): a) generating QoS requirement from characteristics for one or more packets to be transmitted via a sidelink; b) determining bearer configuration corresponding to the QoS requirement; and c) performing SL transmission on the basis of the bearer configuration.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 17/265,952 filed on Feb. 4, 2021, which itself is a 35 U.S.C. § 371national stage application of PCT International Application No.PCT/EP2019/071457 filed on Aug. 9, 2019, which itself is a continuationof PCT International Application No. PCT/CN2018/100024 filed Aug. 10,2018, the disclosures and contents of which are incorporated byreference herein in their entireties.

TECHNICAL FIELD

The present application generally relates to wireless communicationtechnology. More particularly, the present application relates to amethod and apparatus for controlling sidelink (SL) QoS. The presentapplication also relates to apparatus and computer program productadapted for the same purpose.

BACKGROUND

Currently, there are many Use Cases (UCs) under discussion withinVehicle to Everything or V2X context, e.g., platooning, cooperativedriving, car following and hazard zone warning etc. Many of them havestringent requirements on QoS, e.g., 99.9% reliability and 50 ms maximumlatency.

In the Uu interface (radio interface between the mobile and the radioaccess network), QoS control is handled on bearer level in Long TermEvolution (LTE) and on QoS flow level in 5GS. Different from the QoScontrol mechanism used in cellular network, QoS control in Sidelink (SL)is based on the concept of ProSe Per-Packet Priority (PPPP) and ProSePer-Packet Reliability (PPPR). When the ProSe upper layer (i.e., abovePC5 access stratum) passes a protocol data unit for transmission to thePC5 access stratum, the ProSe upper layer provides a ProSe Per-PacketPriority from a range of 8 possible values. Each PPPP expresses arelative priority compared to other PPPPs, i.e., PPPP=1 has highestpriority than PPPP=2, PPPP=3, etc. PPPPs also expresses the relativelatency requirements, i.e., PPPP=1 has more stringent packet delaybudget (PDB) requirements than PPPP=2, PPPP=3, etc. Additionally, alongwith the PPPP, upper layers may also indicate the PPPR value of a givenpacket. Priority queues (both intra-UE and inter-UE) are expected to beserved in priority order i.e., UE (User Equipment) serves all packetsassociated with ProSe Per-Packet Priority N before serving packetsassociated with priority N+1 (lower number meaning higher priority).Similarly, the PPPR is used to determine whether SL packet duplicationto enhance transmission reliability shall be used or not.

When a network (NW) scheduled operation mode (also known as mode-3) isused, NW configures a mapping between Logical Channel Groups (LCGs) andPPPPs for the sake of Sidelink Buffer Status Report (SL-BSR) reporting,and UE indicates in SL-BSR the LCGs for which there are packets totransmit over the PC5 interface (interface between 2 UEs, also referredas Sidelink interface). When eNB receives the SL-BSR, it can determinewhich are the PPPPs of the packets UE needs to transmit over PC5,thereby also inferring the priority info and the packet delay budget.eNB can use the priority information reflecting PPPP for priorityhandling and UE-PC5-Aggregate Maximum Bit Rate (AMBR) for capping the UEPC5 transmission in the resources management. For the case of PPPR,eNB/gNB may reserve one or more LCGs for PPPPR reporting. Upon receivingthe SL-BSR, the eNB/gNB can, for example, decide whether to enablepacket duplication or not.

In an autonomous resources selection mode (referring to as mode-4), PPPPis contained in SCI to avoid other UEs transmitting on the high priorityresources. UE derives the packet delay budget of the V2X message fromPPPP based on the provisioned mapping information described.

SUMMARY

One of the objects is to provide methods and apparatus for controllingsidelink (SL) QoS in a cellular network, which could provide more solidsidelink QoS.

According to one embodiment, a method for controlling sidelink (SL)Quality of Service (QoS) in a cellular network comprises the followingsteps carried out at a network node:

-   -   a) in response to a SL bearer request indicating QoS requirement        from a user equipment (UE), determining whether the bearer        request is accepted on the basis of SL resources usage in a        cellular network;    -   b) if accepted, determining bearer configuration for SL        transmission by the UE on the basis of the QoS requirement; and    -   c) transmitting the bearer configuration to the UE.

According to another embodiment, an apparatus for controlling sidelink(SL) QoS in a cellular network comprises:

-   -   a storage device configured to store a computer program        comprising computer instructions; and    -   a processor coupled to the storage device and configured to        execute the computer instructions to:    -   a) in response to a bearer request indicating Quality of Service        (QoS) requirement from a User Equipment (UE), determining        whether the bearer request is accepted on the basis of SL        resources usage in a cellular network;    -   b) if accepted, determining bearer configuration for SL        transmission by the UE on the basis of the QoS requirement; and    -   c) transmitting the bearer configuration to the UE.

According to another embodiment, a method for controlling sidelink (SL)Quality of Service (QoS) in a cellular network, comprises the followingsteps carried out at a network node:

-   -   a) in response to attachment to the cellular network or location        update of a User Equipment (UE), determining bearer        configuration for SL transmission by the UE; and    -   b) transmitting the bearer configuration to the UE.

According to another embodiment, an apparatus for controlling sidelink(SL) Quality of Service (QoS) in a cellular network comprises:

-   -   a storage device configured to store a computer program        comprising computer instructions; and    -   a processor coupled to the storage device and configured to        execute the computer instructions to:        -   a) in response to attachment to the cellular network or            location update for a User Equipment (UE), determining            bearer configuration for SL transmission by the UE; and        -   b) transmitting the bearer configuration to the UE.

According to another embodiment, a method for controlling sidelink (SL)Quality of Service (QoS) in a cellular network comprises the followingsteps carried out at a network node:

-   -   a) determining bearer configuration for SL transmission by a        User Equipment (UE) in an Radio Resource Control (RRC) idle mode        in the cellular network; and    -   b) broadcasting the bearer configuration in one or more cells of        the cellular network.

According to another embodiment, an apparatus for controlling sidelink(SL) Quality of Service (QoS) in a cellular network comprises:

-   -   a storage device configured to store a computer program        comprising computer instructions; and    -   a processor coupled to the storage device and configured to        execute the computer instructions to:        -   a) determining bearer configuration for SL transmission by a            User Equipment (UE) in an Radio Resource Control (RRC) idle            mode in the cellular network; and        -   b) broadcasting the bearer configuration in one or more            cells of the cellular network.

According to another embodiment, a method for controlling sidelink (SL)Quality of Service (QoS) in a cellular network comprises the followingsteps carried out at a User Equipment (UE):

-   -   a) generating QoS requirement from characteristics for one or        more packets to be transmitted via a sidelink;    -   b) transmitting a bearer request comprising the QoS requirement        to a network node; and    -   c) performing SL transmission on the basis of bearer        configuration received from the network node, wherein the bearer        configuration is determined on the basis of the QoS requirement.

According to another embodiment, a User Equipment (UE) operating in acellular network with sidelink (SL) Quality of Service (QoS) controllingfunction comprises:

-   -   a storage device configured to store a computer program        comprising computer instructions; and    -   a processor coupled to the storage device and configured to        execute the computer instructions to:        -   a) generating QoS requirement from characteristics for one            or more packets to be transmitted via a sidelink;        -   b) transmitting a bearer request comprising the QoS            requirement to a network node; and        -   c) performing SL transmission on the basis of bearer            configuration received from the network node, wherein the            bearer configuration is determined on the basis of the QoS            requirement.

According to another embodiment, a method for controlling sidelink (SL)Quality of Service (QoS) comprises the following steps carried out at aUser Equipment (UE):

-   -   a) generating QoS requirement from characteristics for one or        more packets to be transmitted via a sidelink;    -   b) determining bearer configuration corresponding to the QoS        requirement; and    -   c) performing SL transmission on the basis of the bearer        configuration.

According to another embodiment, a User Equipment (UE) with sidelink(SL) Quality of Service (QoS) controlling function comprises:

-   -   a storage device configured to store a computer program        comprising computer instructions; and    -   a processor coupled to the storage device and configured to        execute the computer instructions to:        -   a) generating QoS requirement from characteristics for one            or more packets to be transmitted via a sidelink;        -   b) determining bearer configuration corresponding to the QoS            requirement; and        -   c) performing SL transmission on the basis of the bearer            configuration.

Current SL QoS control is based on basic relativepriorities/reliabilities requirements differences, which can only securethe QoS of some particular UEs is better than that of other UEs butcannot secure an explicitly required QoS level, e.g., 20 ms latency, ofa particular V2X service of a UE. Moreover, for the UE using mode4 (UEautonomous resource selection), it is even worse, when all transmittingUEs are sharing resources. The QoS is mainly depending on the size ofresource pool, and the number of UEs being using the pool. According toone or more embodiments, it provides mechanisms to improve SL QoScontrol enforcement. In particular, QoS requirement may be determined atUE and then mapped into the corresponding data radio bearer fortransmission according to the bearer configuration determined at networknode. Furthermore, admission control could also be applied to help NWreject SL bearer requests when the channel is full or preempt lowpriority bearers for high priority ones.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages would beapparent from the following more particular description of preferredembodiments as illustrated in the accompanying drawings in which:

FIG. 1 is a flow diagram illustrating a process for controlling sidelink(SL) Quality of Service (QoS) in a cellular network according to one ormore exemplary embodiment.

FIG. 2 shows an example of NW SL QoS enforcement for In-Coverageconnected mode according to one or more exemplary embodiment.

FIG. 3 is a block diagram illustrating an apparatus for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

FIG. 4 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

FIG. 5 is another block diagram illustrating an apparatus forcontrolling sidelink (SL) Quality of Service (QoS) in a cellular networkaccording to one or more exemplary embodiment.

FIG. 6 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

FIG. 7 is another block diagram illustrating an apparatus forcontrolling sidelink (SL) Quality of Service (QoS) in a cellular networkaccording to one or more exemplary embodiment.

FIG. 8 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

FIG. 9 is another block diagram illustrating a User Equipment (UE)operating in a cellular network with sidelink (SL) Quality of Service(QoS) controlling function according to one or more exemplaryembodiment.

FIG. 10 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

FIG. 11 is another block diagram illustrating A User Equipment (UE)operating in a cellular network with sidelink (SL) Quality of Service(QoS) controlling function according to one or more exemplaryembodiment.

DETAILED DESCRIPTION

The invention can be implemented in numerous ways, including as aprocess; an apparatus; a system; a composition of matter; a computerprogram product embodied on a computer readable storage medium; and/or aprocessor, such as a processor configured to execute instructions storedon and/or provided by a memory coupled to the processor. In thisspecification, these implementations, or any other form that theinvention may take, may be referred to as techniques. In general, theorder of the steps of disclosed processes may be altered within thescope of the invention. Unless stated otherwise, a component such as aprocessor or a memory described as being configured to perform a taskmay be implemented as a general component that is temporarily configuredto perform the task at a given time or a specific component that ismanufactured to perform the task. As used herein, the term “processor”refers to one or more devices, circuits, and/or processing coresconfigured to process data, such as computer program instructions.

A detailed description of one or more embodiments of the invention isprovided below along with accompanying figures that illustrate theprinciples of the invention. The invention is described in connectionwith such embodiments, but the invention is not limited to anyembodiment. The scope of the invention is limited only by the claims andthe invention encompasses numerous alternatives, modifications andequivalents. Numerous specific details are set forth in the followingdescription in order to provide a thorough understanding of theinvention. These details are provided for the purpose of example and theinvention may be practiced according to the claims without some or allof these specific details. For the purpose of clarity, technicalmaterial that is known in the technical fields related to the inventionhas not been described in detail so that the invention is notunnecessarily obscured.

As used herein, the term “User Equipment (UE)” refers to a device useddirectly by an end-user to communicate. The non-exclusive examples ofthe UE include a hand-held telephone, a laptop computer equipped with amobile broadband adapter, or any other device.

FIG. 1 is a flow diagram illustrating a process for controlling sidelink(SL) Quality of Service (QoS) in a cellular network according to one ormore exemplary embodiment.

With reference to FIG. 1 , at step 101, a network node, such as eNB/gNB,V2X control function or V2X server Node receives a SL bearer requestfrom a user equipment (UE). The SL bearer request indicates QoSrequirement, which, e.g., reflects QoS demand for SL transmission by theUE. In one embodiment, the QoS requirement is represented as one of 5GQoS Indicator (5QI), QoS Class Identifier (QCI), ProSe Per-PacketPriority (PPPP) or ProSe Per-Packet Reliability (PPPR).

At step 102, the network node determines whether the bearer request isaccepted on the basis of SL resources usage in the cellular network. Ifaccepted, the process proceeds to step 103, which will be described indetail; otherwise, it proceeds to step 104 where the network nodetransmits to the UE a notification that the SL bearer request isrejected.

Due to limited resources, it is necessary for the network node tocontrol the number of UEs which are transmitting via sidelink at thesame time. Preferably, at step 102, the determining is performed asfollows:

-   -   if there are SL resources sufficient to fulfill the QoS        requirement, the bearer request will be accepted;    -   if after dropping other bearer(s) with lower priority, there are        SL resources sufficient to fulfill the QoS requirement, the        bearer request will be accepted; and    -   if after dropping other bearer(s) with lower priority, there are        still no SL resources to fulfill the QoS requirement, the bearer        request will be rejected.

In one embodiment, the SL resources are in form of one or more resourcepools, each of which corresponds to a respective QoS requirement.Moreover, the network node can configure the resource poolsindividually. In some cases, the configuration for the resource poolscan be adjusted at the network node by, e.g., adding new resourcepool(s) or increasing the size of at least one of the resource pools.

In one embodiment, the network node may configure a plurality ofresource pools corresponding to different QoS requirements. Severalpools may be designated to one QoS requirement. For each pool, thenetwork node evaluates whether the SL transmission by a new UE willdegrade the QoS performance for the existing users in the pool. Forexample, the network node may specify some pools as ones where their QoSperformance is not allowed to degrade. To this end, the network node maygrant the pool with the least load to the new UE. If no pool satisfyingthe above criteria is available, the network node may carry out at leastone of the following operations:

-   -   adjusting resource pool configuration and searching the pool        satisfying the above criteria again;    -   revoking existing bearers from other UEs and accepting the        bearer request;    -   rejecting the SL bearer request from the new UE.

Preferably, a QoS threshold and a congestion level threshold can beassigned to one or more resource pools. With such configuration, the UEis allowed to use the resource pools for the SL transmission (only) if acongestion level of the resource pools is lower than the congestionlevel threshold for the QoS threshold. For example, the network node mayassign different QoS threshold and different associated congestion levelto the same pool. The UE is allowed to start transmitting packets havinga certain QoS on a given pool (only) if the congestion level (such asCBR) of such pool is lower than a certain congestion level threshold forthe concerned QoS level. The UE shall stop using such pool if thecongestion degrades above another congestion level for the concerned QoSlevel.

Turning to step 103, where the network node determines bearerconfiguration for SL transmission by the UE on the basis of the QoSrequirement. Preferably, the determining may be performed as follows:

-   -   retrieving an index corresponding to the QoS requirement;    -   if succeeding, generating or obtaining the bearer configuration        associated with the index; and    -   if failed, transmitting a notification that the QoS requirement        is not supported by the cellular network.

In one embodiment, in the case where the QoS requirement is notsupported by the cellular network, the UE may either drop thecorresponding QoS session/QoS flow/packet transmission or perform SLtransmissions in best effort strategy. For example, the UE may use theresources provided by the network for low priority transmissions where,for example, no latency requirements, bit rate, can be guaranteed. Inanother embodiment, the network node may transmit to the UE informationspecifying which QoS requirement(s) can be supported in order to avoidnon-supportable QoS demand from the UE. Preferably, the information istransmitted during an attachment procedure or via a System InformationBlock (SIB).

In one embodiment, preferably, the bearer configuration comprises amapping relationship between the QoS requirement and a SL Data RadioBearer (DRB). Optionally, the bearer configuration may further compriseone or more transmitting parameters. More preferably, the transmittingparameters comprises at least one of transmitting power for SLtransmission, Modulation Coding Scheme (MCS), carrier aggregation,packet duplication configuration, and SL resources being used.

Then, the process proceeds to step 105 where the network node transmitsthe bearer configuration as determined at step 104 to the UE. Uponreception of the bearer configuration, at the UE, a SDAP layer maps theQoS flows, e.g., the QCI/5QI of the incoming packets/QoS flows into PC5data radio bearer associated with the corresponding LCID as indicated inthe bearer configuration.

Optionally, the process proceeds to step 106 where the network nodedetermines bearer reconfiguration for SL transmission on the basis ofQoS performance. For example, in one embodiment, the network node maykeep monitoring the QoS performance during the time based on feedbacksand reports sent from SL UEs. Link adaptation can be applied to achievethe required QoS. If the required QoS cannot be fulfilled during acertain amount of time, the current bearer will be modified or revoked.

FIG. 2 shows an example of NW SL QoS enforcement for In-Coverageconnected mode according to one or more exemplary embodiment.

In the scenario as shown in FIG. 2 , TxUE and RxUE are in coverage andoperate in RRC connected mode, an explicit permission from the NW isneeded to establish and configure a SL bearer. Referring to FIG. 2 ,after an authentication procedure succeeds, TxUE sends a SL bearerrequest to NW for activating SL service. The information related to theSL bearer request can be sent via RRC, e.g., as part of SLUeInformationsignal, including 5QI/QCI packets currently in an SL buffer, or relatedto SL QoS flows. For example, the SL bearer request can be sent uponindication from upper layers that a certain V2X QoS session shall beinitiated over a PC5 interface.

In one implementation, the 5QI/QCI reported to NW in the SL bearerrequest are addressed by an index which is given to the UE via dedicatedor SIB signaling by NW for each possible 5QI/QCI. In case a given5QI/QCI is not associated with any index, it indicates that NW does notsupport NW controlled QoS for that specific 5QI/QCI in a concerned cell.In this case, TxUE shall either drop the corresponding QoS session/QoSflow/packet transmission, in which case AS layers at TxUE may indicateupper layers that such packet/QoS sessions/QoS flow shall be dropped, orperform transmissions of such QoS flow in best effort fashion, e.g., UEmay use a pool of resources provided by NW for low prioritytransmissions where, for example, no latency requirements, bit rate, canbe guaranteed. To this end, NW may indicate unallowable QCI/5QI in theconcerned cell or indicate allowable QCI/5QI instead.

Referring to FIG. 2 , upon reception of the SL bearer request, based onthe current load in sidelink channel, NW determines whether the demandedQoS can be supported and returns acceptation or rejection accordingly.It shall be noted that if channel is unavailable, NW shall drop some lowpriority bearers in order to support the requested bearer with higherpriority.

If the SL bearer request is accepted, NW will also configure, e.g., viaRRC reconfiguration signaling, QoS to data radio bearer mapping in SLUE, e.g., SDAP layer. Such signal may indicate the mapping between the5QI/QCI previously signaled in the SL bearer request and a PC5 DRBidentity such as LCID, LCG, and a set of transmitting parameterconfiguration such as transmitting power, Modulation Coding Scheme(MCS), carrier aggregation, packet duplication configuration, and SLresources being used.

Upon reception of the bearer configuration from NW, at TxUE, the SDAPlayer maps QoS flows, i.e., the QCI/5QI of the incoming packets/QoSflows into PC5 data radio bearer associated with the corresponding LCIDas indicated in the bearer configuration by NW.

As shown in FIG. 2 , NW keeps monitoring the QoS performance during thetime based on feedbacks and reports sent from SL UEs, e.g., RxUE. Linkadaptation can be applied to achieve the required QoS. If the requiredQoS cannot be fulfilled during a certain amount of time, the currentbearer will be modified or revoked.

FIG. 3 is a block diagram illustrating an apparatus for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiments.

With reference to FIG. 3 , the apparatus 30 comprises a storage device310 and a processor 320 coupled to the storage device 310. The storagedevice 310 is configured to store a computer program 330 comprisingcomputer instructions. The processor 320 is configured to execute thecomputer instructions to perform some or all of the method steps asshown in FIGS. 1 and 2 .

FIG. 4 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

With reference to FIG. 4 , at step 401, a network node, such as eNB/gNB,V2X control function or V2X server Node determines bearer configurationfor SL transmission by the UE in response to attachment to the cellularnetwork or location update of a User Equipment (UE).

In one embodiment, preferably, the bearer configuration is determinedbased on an operational mode in which the UE operates, and theoperational mode comprise a Radio Resource Control (RRC) connected modeand a RRC idle mode. That is, depending on the operational mode in whichthe UE operates, the network node may determine different bearerconfigurations for the UE. Moreover, when mode 3 UEs and mode 4 UEs areusing the same resource pool, the same bearer configuration can beapplied, and vice versa.

In one embodiment, the bearer configuration provides QoS to data radiobearer mapping, which specifies, e.g., the usage of resource pools, LCIDand LCG for each possible QoS flow. The network node may update the QoSto data radio bearer mapping.

In the process as shown in FIG. 4 , SL UEs do not need explicitpermission from NW before SL transmitting via a bearer. Instead these SLUEs will perform SL transmission on the basis of the bearerconfiguration from the network node during attachment procedure.

In one embodiment, preferably, the bearer configuration comprises amapping relationship between the QoS requirement and a SL Data RadioBearer (DRB). Optionally, the bearer configuration may further compriseone or more transmitting parameters. More preferably, the transmittingparameters comprises at least one of transmitting power for SLtransmission, Modulation Coding Scheme (MCS), carrier aggregation,packet duplication configuration, and SL resources being used.

In another embodiment, the network node may transmit to the UEinformation specifying which QoS requirement(s) can be supported inorder to avoid non-supportable QoS demand from the UE. Preferably, theinformation is transmitted during an attachment procedure or via aSystem Information Block (SIB).

Then, the process proceeds to step 402 where the network node transmitsthe bearer configuration as determined at step 401 to the UE.

FIG. 5 is another block diagram illustrating an apparatus forcontrolling sidelink (SL) Quality of Service (QoS) in a cellular networkaccording to one or more exemplary embodiment.

With reference to FIG. 5 , the apparatus 50 comprises a storage device510 and a processor 520 coupled to the storage device 510. The storagedevice 510 is configured to store a computer program 530 comprisingcomputer instructions. The processor 520 is configured to execute thecomputer instructions to perform some or all of the method steps asshown in FIG. 4 .

FIG. 6 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

With reference to FIG. 6 , at step 601, a network node, such as eNB/gNB,V2X control function or V2X server Node determines bearer configurationfor SL transmission by the UE, which operates in a Radio ResourceControl (RRC) idle mode.

In one embodiment, preferably, the bearer configuration comprises amapping relationship between the QoS requirement and a SL Data RadioBearer (DRB) Optionally, the bearer configuration may further compriseone or more transmitting parameters. More preferably, the transmittingparameters comprises at least one of transmitting power for SLtransmission, Modulation Coding Scheme (MCS), carrier aggregation,packet duplication configuration, and SL resources being used.

Then, the process proceeds to step 602 where the network node broadcaststhe bearer configuration as determined at step 601 in one or more cellsof the cellular network where the UE resides. Preferably, the bearerconfiguration is broadcasted via a System Information Block (SIB). Morepreferably, the network node may transmit to the UE informationspecifying which QoS requirement(s) can be supported via a SystemInformation Block (SIB).

Likewise, in the process as shown in FIG. 6 , SL UEs do not needexplicit permission from NW before SL transmitting via a bearer. Insteadthese SL UEs will perform SL transmission on the basis of the bearerconfiguration receiving from the network node while in the RRC idlemode.

FIG. 7 is another block diagram illustrating an apparatus forcontrolling sidelink (SL) Quality of Service (QoS) in a cellular networkaccording to one or more exemplary embodiment.

With reference to FIG. 7 , the apparatus 70 comprises a storage device710 and a processor 720 coupled to the storage device 710. The storagedevice 710 is configured to store a computer program 730 comprisingcomputer instructions. The processor 720 is configured to execute thecomputer instructions to perform some or all of the method steps asshown in FIG. 6 .

FIG. 8 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

With reference to FIG. 8 , at step 801, a UE generates QoS requirementfrom characteristics for one or more packets to be transmitted via asidelink.

In one embodiment, preferably, the characteristics are defined in apacket header complying with a protocol layer above Access Stratum (AS).For example, the protocol layer above AS may be transport layer ornetwork layer where IP is used for transmission over PC5 or ITS facilitylayer where geo-networking is used for transmission over PC5. As anexample, the characteristics may be represented as classical 5-tuple IPcharacteristics, e.g., source IP address, destination IP address, sourceport number, destination port number, protocol in use. Alternatively,the characteristic may be represented as geo-networking packetproperties, e.g., Source port, Destination port, Geo-Networking (GN)Destination address, GN Repetition interval indicating the periodicityof a given packet transmission, GN Maximum repetition time indicatingthe latency budget of a packet transmission, GN Traffic class, etc.Also, the specific V2X service in the form of PSID or ITS-AIDs can beindicated.

In one embodiment, preferably, the generating is performed by convertingthe characteristics into corresponding QoS requirement on the basis of amapping relationship between the characteristics and the QoSrequirement. For example, the mapping relationship may be representedwith a table including one or more entries, each defining a combinationof the characteristic and the QoS requirement. Preferably, each entrymay be assigned an index, e.g., one as described with reference to FIG.1 .

The mapping relationship may be provided by the network node and can beupdated by the network node. For example, the mapping relationship maybe provided with NAS/AS signaling (e.g., RRC/SIB) and/or represented aspart of RRC preconfiguration.

In one embodiment, the mapping relationship can be provided while the UEentering radio NW coverage, and this can be performed by a network nodesuch as the eNB/gNB, V2X control function or by a policy controlfunction (PCF), or by a unified data repository (UDR), or by V2X server,or preconfigured in Universal Integrated Card (UICC) and/or MobileEquipment (ME). Alternatively, the mapping relationship can be providedvia dedicated NAS or AS signaling in case the UE is in connected mode orvia broadcast signaling (e.g., SIB) in case the UE is in idle mode.

In another embodiment, the mapping relationship depends on anoperational mode, e.g., RRC connected mode, RRC idle mode or Out ofCoverage (OoC) mode, in which the UE operates. Preferably, one or morecandidate mapping relationships between the characteristics and the QoSrequirement can be received from the network node and stored at the UE,each of which corresponds to one or more operational modes, and theoperational mode comprises a Radio Resource Control (RRC) connectedmode, a RRC idle mode and an Out of Coverage (OoC) mode. Morepreferably, the mapping relationship between the characteristics and theQoS requirement is selected from the one or more candidate mappingrelationships depending on which operational mode the UE operates in.

At step 802, the UE transmits a bearer request comprising the QoSrequirement as generated at step 801 to a network node. As describedabove, the network node may determine whether the bearer request isaccepted on the basis of SL resources usage in the cellular network, andif accepted, it will transmit bearer configuration to the UE; otherwise,it will transmit to the UE a notification that the SL bearer request isrejected.

Then, the process proceeds to step 803 where the UE determines whetherthe SL bearer request is accepted or rejected. If accepted, it proceedsto step 804, and if rejected, it proceeds to step 805.

At step 804, the UE performs SL transmission on the basis of the bearerconfiguration received from the network node. For example, uponreception of the bearer configuration, at the UE, a Service DataAdaption Protocol (SDAP) layer maps the QoS flows, e.g., the QCI/5QI ofthe incoming packets/QoS flows into PC5 data radio bearer associatedwith the corresponding LCID as indicated in the bearer configuration.

On the other hand, at step 805, the UE may either drop the correspondingQoS session/QoS flow/packet transmission or perform SL transmissions inbest effort strategy. For example, the UE may use the resources providedby the network for low priority transmissions where, for example, nolatency requirements, bit rate, can be guaranteed.

In one embodiment, preferably, the bearer configuration comprises amapping relationship between the QoS requirement and a SL Data RadioBearer (DRB). Optionally, the bearer configuration may further compriseone or more transmitting parameters. More preferably, the transmittingparameters comprises at least one of transmitting power for SLtransmission, Modulation Coding Scheme (MCS), carrier aggregation,packet duplication configuration, and SL resources being used.

FIG. 9 is another block diagram illustrating a User Equipment (UE)operating in a cellular network with sidelink (SL) Quality of Service(QoS) controlling function according to one or more exemplaryembodiment.

With reference to FIG. 9 , UE 90 comprises a storage device 910 and aprocessor 920 coupled to the storage device 910. The storage device 910is configured to store a computer program 930 comprising computerinstructions. The processor 920 is configured to execute the computerinstructions to perform some or all of the method steps as shown in FIG.8 .

FIG. 10 is another flow diagram illustrating a process for controllingsidelink (SL) Quality of Service (QoS) in a cellular network accordingto one or more exemplary embodiment.

With reference to FIG. 10 , at step 1001, a UE generates QoS requirementfrom characteristics for one or more packets to be transmitted via asidelink.

In one embodiment, preferably, the characteristics are defined in apacket header complying with a protocol layer above Access Stratum (AS).For example, the protocol layer above AS may be transport layer ornetwork layer where IP is used for transmission over PC5 or ITS facilitylayer where geo-networking is used for transmission over PC5. As anexample, the characteristics may be represented as classical 5-tuple IPcharacteristics, e.g., source IP address, destination IP address, sourceport number, destination port number, protocol in use. Alternatively,the characteristic may be represented as geo-networking packetproperties, e.g., Source port, Destination port, GN Destination address,GN Repetition interval indicating the periodicity of a given packettransmission, GN Maximum repetition time indicating the latency budgetof a packet transmission, GN Traffic class, etc. Also, the specific V2Xservice in the form of PSID or ITS-AIDs can be indicated.

In one embodiment, preferably, the generating is performed by convertingthe characteristics into corresponding QoS requirement on the basis of amapping relationship between the characteristics and the QoSrequirement. For example, the mapping relationship may be representedwith a table including one or more entries, each defining a combinationof the characteristic and the QoS requirement. Preferably, each entrymay be assigned an index, e.g., one as described with reference to FIG.1 .

The mapping relationship may be provided by the network node and can beupdated by the network node. For example, the mapping relationship maybe provided with Non-Access-Stratum/Access-Stratum (NAS/AS) signaling(e.g., RRC/SIB) and/or represented as part of RRC preconfiguration.

In one embodiment, the mapping relationship can be provided while the UEentering radio NW coverage, and this can be performed by a network nodesuch as the eNB/gNB, V2X control function or by a policy controlfunction (PCF), or by a unified data repository (UDR), or by V2X server,or preconfigured in UICC and/or ME. Alternatively, the mappingrelationship can be provided via dedicated NAS or AS signaling in casethe UE is in connected mode or via broadcast signaling (e.g., SIB) incase the UE is in idle mode.

In another embodiment, the mapping relationship depends on anoperational mode, e.g., RRC connected mode, RRC idle mode or Out ofCoverage (OoC) mode, in which the UE operates. Preferably, one or morecandidate mapping relationships between the characteristics and the QoSrequirement can be received from the network node and stored at the UE,each of which corresponds to one or more operational modes, and theoperational mode comprises a Radio Resource Control (RRC) connectedmode, an RRC idle mode and Out of Coverage (OoC) mode. More preferably,the mapping relationship between the characteristics and the QoSrequirement is selected from the one or more candidate mappingrelationships depending on which operational mode the UE operates in.

Alternatively, the candidate mapping relationships between thecharacteristics and the QoS requirement can be received via broadcastfrom the network node while the UE is in-coverage of the cellularnetwork.

At step 1002, the UE determines bearer configuration corresponding tothe QoS requirement as generated at step 1001. In one embodiment, thedetermining is on the basis of a mapping relationship between the QoSrequirement and the bearer configuration. The mapping relationship canbe received from the network node and stored at the UE. Alternatively,the mapping relationship can be preconfigured at the UE.

Alternatively, the mapping relationship between the QoS requirement andthe bearer configuration can be received via broadcast from the networknode while the UE is in-coverage of the cellular network.

Then, the process proceeds to step 1003 where the UE performs SLtransmission on the basis of the bearer configuration as determined atstep 1002. For example, a SDAP layer can map the QoS flows, e.g., theQCI/5QI of the incoming packets/QoS flows into PC5 data radio bearerassociated with the corresponding Logical Channel Identification (LCID)as indicated in the bearer configuration.

In one embodiment, preferably, the bearer configuration comprises amapping relationship between the QoS requirement and a SL Data RadioBearer (DRB). Optionally, the bearer configuration may further compriseone or more transmitting parameters. More preferably, the transmittingparameters comprises at least one of transmitting power for SLtransmission, Modulation Coding Scheme (MCS), carrier aggregation,packet duplication configuration, and SL resources being used.

FIG. 11 is another block diagram illustrating a User Equipment (UE)operating in a cellular network with sidelink (SL) Quality of Service(QoS) controlling function according to one or more exemplaryembodiment.

With reference to FIG. 11 , UE 110 comprises a storage device 1110 and aprocessor 1120 coupled to the storage device 1110. The storage device1110 is configured to store a computer program 1130 comprising computerinstructions. The processor 1120 is configured to execute the computerinstructions to perform some or all of the method steps as shown in FIG.10 .

According to one or more embodiments of the present invention, a methodfor controlling sidelink (SL) Quality of Service (QoS) in a cellularnetwork, comprises the following steps carried out at a network node:

-   -   a) in response to a SL bearer request indicating QoS requirement        from a user equipment (UE), determining (102) whether the bearer        request is accepted on the basis of SL resources usage in a        cellular network;    -   b) if accepted, determining (103) bearer configuration for SL        transmission by the UE on the basis of the QoS requirement; and    -   c) transmitting (105) the bearer configuration to the UE.

Alternatively, the step a) comprises:

-   -   a1) if there are SL resources sufficient to fulfill the QoS        requirement, the network node will accept the bearer request;    -   a2) if after dropping other bearer(s) with lower priority, there        are SL resources sufficient to fulfill the QoS requirement, the        network node will accept the bearer request; and    -   a3) if after dropping other bearer(s) with lower priority, there        are still no SL resources to fulfill the QoS requirement, the        network node will reject the bearer request.

Alternatively, the SL resources are in form of one or more resourcepools, each of which corresponds to a respective QoS requirement.

Alternatively, configuration for the resource pools can be adjusted byadding new resource pool(s) or increasing the size of at least one ofthe resource pools.

Alternatively, a QoS threshold and a congestion level threshold areassigned to at least one of the resource pools and the UE is allowed touse the at least one of the resource pools for the SL transmission if acongestion level of the at least one of the resource pools is lower thanthe congestion level threshold for the QoS threshold.

Alternatively, the QoS requirement is represented as one of 5G QoSIndicator (5QI), QoS Class Identifier (QCI), ProSe Per-Packet Priority(PPPP) or ProSe Per-Packet Reliability (PPPR).

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, the method further comprises the step of determiningbearer reconfiguration for SL transmission on the basis of QoSperformance.

Alternatively, the step b) comprises:

-   -   retrieving an index corresponding to the QoS requirement; and    -   if failed, transmitting a notification that the QoS requirement        is not supported.

Alternatively, the method further comprises the step of signaling to theUE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, anapparatus (30) for controlling sidelink (SL) QoS in a cellular networkcomprises:

-   -   a storage device (310) configured to store a computer program        (320) comprising computer instructions; and    -   a processor (320) coupled to the storage device and configured        to execute the computer instructions to:        -   a) in response to a bearer request indicating Quality of            Service (QoS) requirement from a User Equipment (UE),            determining (102) whether the bearer request is accepted on            the basis of SL resources usage in a cellular network;        -   b) if accepted, determining (103) bearer configuration for            SL transmission by the UE on the basis of the QoS            requirement; and        -   c) transmitting (105) the bearer configuration to the UE.

Alternatively, the step a) comprises:

-   -   a1) if there are SL resources sufficient to fulfill the QoS        requirement, the network node will accept the bearer request;    -   a2) if after dropping other bearer(s) with lower priority, there        are SL resources sufficient to fulfill the QoS requirement, the        network node will accept the bearer request; and    -   a3) if after dropping other bearer(s) with lower priority, there        are still no SL resources to fulfill the QoS requirement, the        network node will reject the bearer request.

Alternatively, the SL resources are in form of one or more resourcepools, each of which corresponds to a respective QoS requirement.

Alternatively, configuration for the resource pools can be adjusted byadding new resource pool(s) or increasing the size of at least one ofthe resource pools.

Alternatively, a QoS threshold and a congestion level threshold areassigned to at least one of the resource pools and the UE is allowed touse the at least one of the resource pools for the SL transmission if acongestion level of the at least one of the resource pools is lower thanthe congestion level threshold for the QoS threshold.

Alternatively, the QoS requirement is represented as one of 5G QoSIndicator (5QI), QoS Class Identifier (QCI), ProSe Per-Packet Priority(PPPP) or ProSe Per-Packet Reliability (PPPR).

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, the apparatus (30) is further configured for determiningbearer reconfiguration for SL transmission on the basis of QoSperformance.

Alternatively, the step b) comprises:

-   -   retrieving an index corresponding to the QoS requirement; and    -   if failed, transmitting a notification that the QoS requirement        is not supported.

Alternatively, the apparatus (30) is further configured for signaling tothe UE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, a methodfor controlling sidelink (SL) Quality of Service (QoS) in a cellularnetwork comprises the following steps carried out at a network node:

-   -   a) in response to attachment to the cellular network or location        update of a User Equipment (UE), determining (401) bearer        configuration for SL transmission by the UE; and    -   b) transmitting (402) the bearer configuration to the UE.

Alternatively, at step a), the bearer configuration is determined basedon an operational mode in which the UE operates, and the operationalmode comprise a Radio Resource Control (RRC) connected mode and an RRCidle mode.

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, the method further comprises the step of signaling to theUE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, anapparatus (50) for controlling sidelink (SL) Quality of Service (QoS) ina cellular network comprises:

-   -   a storage device (510) configured to store a computer program        (530) comprising computer instructions; and    -   a processor (520) coupled to the storage device and configured        to execute the computer instructions to:        -   a) in response to attachment to the cellular network or            location update for a User Equipment (UE), determining (401)            bearer configuration for SL transmission by the UE; and        -   b) transmitting (402) the bearer configuration to the UE.

Alternatively, at step a), the bearer configuration is determined basedon an operational mode in which the UE operates, and the operationalmode comprise a Radio Resource Control (RRC) connected mode and an RRCidle mode.

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, the apparatus (50) is further configured for signaling tothe UE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, a methodfor controlling sidelink (SL) Quality of Service (QoS) in a cellularnetwork comprises the following steps carried out at a network node:

-   -   a) determining (601) bearer configuration for SL transmission by        a User Equipment (UE) in an Radio Resource Control (RRC) idle        mode in the cellular network; and    -   b) broadcasting (602) the bearer configuration in one or more        cells of the cellular network.

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises and a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, at step b), the bearer configuration is broadcasted via aSystem Information Block (SIB).

Alternatively, the method further comprises the step of signaling to theUE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, anapparatus (70) for controlling sidelink (SL) Quality of Service (QoS) ina cellular network comprises:

-   -   a storage device (710) configured to store a computer program        (730) comprising computer instructions; and    -   a processor (720) coupled to the storage device and configured        to execute the computer instructions to:        -   a) determining (601) bearer configuration for SL            transmission by a User Equipment (UE) in an Radio Resource            Control (RRC) idle mode in the cellular network; and        -   b) broadcasting (602) the bearer configuration in one or            more cells of the cellular network.

Alternatively, the bearer configuration comprises a mapping relationshipbetween the QoS requirement and a SL Data Radio Bearer (DRB).

Alternatively, the bearer configuration further comprises a transmitparameter.

Alternatively, the transmit parameter comprises at least one oftransmitting power for SL transmission, Modulation Coding Scheme (MCS),carrier aggregation, packet duplication configuration, and SL resourcesbeing used.

Alternatively, at step b), the bearer configuration is broadcasted via aSystem Information Block (SIB).

Alternatively, the apparatus (70) is further configured for signaling tothe UE information specifying which QoS requirement(s) are supported.

According to one or more embodiments of the present invention, a methodfor controlling sidelink (SL) Quality of Service (QoS) in a cellularnetwork comprises the following steps carried out at a User Equipment(UE):

-   -   a) generating (801) QoS requirement from characteristics for one        or more packets to be transmitted via a sidelink;    -   b) transmitting (802) a bearer request comprising the QoS        requirement to a network node; and    -   c) performing (804) SL transmission on the basis of bearer        configuration received from the network node, wherein the bearer        configuration is determined on the basis of the QoS requirement.

Alternatively, the characteristics are defined in a packet headercomplying with a protocol layer above Access Stratum (AS).

Alternatively, the step a) comprises converting the characteristics intocorresponding QoS requirement on the basis of a mapping relationshipbetween the characteristics and the QoS requirement.

Alternatively, the mapping relationship is received from the networknode and stored at the UE, or preconfigured at the UE.

Alternatively, one or more candidate mapping relationships are receivedfrom the network node and stored at the UE, each of which corresponds toone or more operational modes, and the operational mode comprises aRadio Resource Control (RRC) connected mode, an RRC idle mode and Out ofcoverage (OoC) mode.

Alternatively, the mapping relationship is selected from the one or morecandidate mapping relationships depending on which operational mode theUE operates in.

Alternatively, the method further comprises:

-   -   d) if receiving a notification from the network node that the        QoS requirement is not supported, performing (805) the SL        transmission in best effort strategy or cancelling the SL        transmission.

Alternatively, the QoS requirement is represented as an index.

Alternatively, the method further comprises the step of receiving fromthe network node information specifying which QoS requirement(s) aresupported.

Alternatively, the receiving is performed during an attachment procedureor via a System Information Block (SIB).

According to one or more embodiments of the present invention, a UserEquipment (UE) (90) operating in a cellular network with sidelink (SL)Quality of Service (QoS) controlling function comprises:

-   -   a storage device (910) configured to store a computer program        (930) comprising computer instructions; and    -   a processor (930) coupled to the storage device and configured        to execute the computer instructions to:        -   a) generating (801) QoS requirement from characteristics for            one or more packets to be transmitted via a sidelink;        -   b) transmitting (802) a bearer request comprising the QoS            requirement to a network node; and        -   c) performing (804) SL transmission on the basis of bearer            configuration received from the network node, wherein the            bearer configuration is determined on the basis of the QoS            requirement.

Alternatively, the characteristics are defined in a packet headercomplying with a protocol layer above Access Stratum (AS).

Alternatively, the step a) comprises converting the characteristics intocorresponding QoS requirement on the basis of a mapping relationshipbetween the characteristics and the QoS requirement.

Alternatively, the mapping relationship is received from the networknode and stored at the UE, or preconfigured at the UE.

Alternatively, one or more candidate mapping relationships are receivedfrom the network node and stored at the UE, each of which corresponds toone or more operational modes, and the operational mode comprises aRadio Resource Control (RRC) connected mode, an RRC idle mode and Out ofcoverage (OoC) mode.

Alternatively, the mapping relationship is selected from the one or morecandidate mapping relationships depending on which operational mode theUE operates in.

Alternatively, the UE (90) is further configured for:

-   -   d) if receiving a notification from the network node that the        QoS requirement is not supported, performing (805) the SL        transmission in best effort strategy or cancelling the SL        transmission.

Alternatively, the QoS requirement is represented as an index.

Alternatively, the UE is further configured for receiving from thenetwork node information specifying which QoS requirement(s) aresupported.

Alternatively, the receiving is performed during an attachment procedureor via a System Information Block (SIB).

According to one or more embodiments of the present invention, a methodfor controlling sidelink (SL) Quality of Service (QoS) comprises thefollowing steps carried out at a User Equipment (UE):

-   -   a) generating (1001) QoS requirement from characteristics for        one or more packets to be transmitted via a sidelink;    -   b) determining (1002) bearer configuration corresponding to the        QoS requirement; and    -   c) performing (1003) SL transmission on the basis of the bearer        configuration.

Alternatively, the UE is out of coverage of a cellular network.

Alternatively, a mapping relationship between the QoS requirement andthe bearer configuration is received from a network node and stored atthe UE, or preconfigured at the UE.

Alternatively, the characteristics are defined in a packet headercomplying with a protocol layer above Access Stratum (AS).

Alternatively, the step a) comprising converting the characteristicsinto corresponding QoS requirement on the basis of a mappingrelationship between the characteristics and the QoS requirement.

Alternatively, the mapping relationship between the characteristics andthe QoS requirement is received from network node and stored at the UE,or preconfigured at the UE.

Alternatively, one or more candidate mapping relationships between thecharacteristics and the QoS requirement are received from the networknode and stored at the UE, each of which corresponds to one or moreoperational modes, and the operational mode comprises a Radio ResourceControl (RRC) connected mode, an RRC idle mode and Out of coverage (OoC)mode.

Alternatively, the mapping relationship between the characteristics andthe QoS requirement is selected from the one or more candidate mappingrelationships depending on which operational mode the UE operates in.

According to one or more embodiments of the present invention, a UserEquipment (UE) (110) with sidelink (SL) Quality of Service (QoS)controlling function comprises:

-   -   a storage device (1110) configured to store a computer program        (1130) comprising computer instructions; and    -   a processor (1130) coupled to the storage device and configured        to execute the computer instructions to:        -   a) generating (1001) QoS requirement from characteristics            for one or more packets to be transmitted via a sidelink;        -   b) determining (1002) bearer configuration corresponding to            the QoS requirement; and        -   c) performing (1003) SL transmission on the basis of the            bearer configuration.

Alternatively, the UE is out of coverage of a cellular network.

Alternatively, a mapping relationship between the QoS requirement andthe bearer configuration is received from a network node and stored atthe UE, or preconfigured at the UE.

Alternatively, the characteristics are defined in a packet headercomplying with a protocol layer above Access Stratum (AS).

Alternatively, the step a) comprising converting the characteristicsinto corresponding QoS requirement on the basis of a mappingrelationship between the characteristics and the QoS requirement.

Alternatively, the mapping relationship between the characteristics andthe QoS requirement is received from the network node and stored at theUE, or preconfigured at the UE.

Alternatively, one or more candidate mapping relationships between thecharacteristics and the QoS requirement are received from the networknode and stored at the UE, each of which corresponds to one or moreoperational modes, and the operational mode comprises a Radio ResourceControl (RRC) connected mode, an RRC idle mode and Out of coverage (OoC)mode.

Alternatively, the mapping relationship between the characteristics andthe QoS requirement is selected from the one or more candidate mappingrelationships depending on which operational mode the UE operates in.

According to one or more embodiments of the present invention, acomputer program product for controlling sidelink (SL) Quality ofService (QoS) in a cellular network, the computer program product beingembodied in a computer readable storage medium and comprising computerinstructions for carrying out the method as described above.

The following embodiments are presented to further illustrate thedisclosure as described above.

According to one or more embodiments of the present invention, tosupport V2X services, five categories of requirements and five level ofautomations to better group various V2X service requirements aredefined, which are characterized by:

-   -   Payload (Bytes);    -   Transmission rate (Message/Sec);    -   Maximum end-to-end latency (ms);    -   Reliability (%);    -   Data rate (Mbps);    -   Minimum required communication range (meters).

3GPP systems (e.g., LTE and NR), including both Uu and sidelink (SL)interfaces, is expected to fulfil the required Key PerformanceIndicators (KPIs).

QoS Management for Uu

According to one or more embodiments of the present invention QoSmanagement for Uu interface is specified based on QoS parameters, e.g.,5QI, ARP, RQA, GFBR, MFBR, notification control and maximum packet lossrate. Before establishing a QoS flow, which corresponds to a radiobearer, admission control is performed. In case there are not enoughfree resources, the QoS flow may be rejected or an existing QoS flow maybe preempted depending on its ARP. Assuming the QoS flow is accepted, itwill be further treated in the network according to other QoSparameters. Note that a 5QI value corresponds to multiple QoScharacteristics, namely resource type (GBR, Delay critical GBR orNon-GBR), priority level, packet delay budget, packet error rate,averaging window, and maximum Data Burst Volume (for Delay-critical GBRresource type only).

Table 1 gives a comparison between V2X KPIs and QoSparameter/characteristics. It indicates that most of the V2X KPIs arealready covered except transmission rate and minimum requiredcommunication range. Transmission rate can be determined by the networkbased on the data rate, latency, and payload requirements. Minimumrequired communication range is not a necessary QoS characteristic,which could be reflected by the destination address carried in thepacket header, e.g., zone address in a geo-network. Relevant workregarding QoS framework for Uu is ongoing in SA2. Potential RANenhancements for V2X may be developed based on inputs from SA2.

TABLE 1 Comparison between V2X service KPI and QoSparameter/characteristic V2X service KPI QoS parameter/characteristicPayload Maximum data burst volume Transmission rate N/A Maximumend-to-end latency Packet delay budget Reliability Packet error rateData rate GFBR/MFBR Minimum required communication N/A range

QoS Management for SL

According to one or more embodiments of the present invention, QoSmanagement for SL is based on PPPP and/or PPPR. PPPP indicates therelative priority and reflects the latency requirement. PPPR describesthe required reliability level with range from 1 to 8. Each generatedV2X application packet will be configured with a PPPP value andoptionally with a PPPR value. The packet will be treated in the lowerlayers according to PPPP/PPPR. Within one UE, packets with lower PPPP,meaning a low latency requirement, will be transmitted first. Amongmultiple UEs, packets with lower PPPP/PPPR can be transmitted using sameresources occupied by other UEs for higher PPPP packet transmissions. InLTE SL, the mapping between priority and LCID is left for UEimplementation. It means there is no unified QoS handling rule among UEsand greedy UEs are allowed to assign lowest PPPP value to theirgenerated packets.

LTE SL UEs may handle logical channel prioritization differentlydepending on their implementations.

A unified QoS handling rule, e.g., map a packet to a corresponding QoSflow, may be used for NR SL UEs.

Besides, there may be no explicit admission control mechanism in SL.Currently, when channel is full, UEs with low PPPP packets are allowedto transmit using those resources occupied by other UEs with high PPPPpackets. As a consequence, severe collision will occur until collidedtransmitters drive far away from each other or a UE reselects itsresource. A more concrete admission control may be needed in SL, suchthat a V2X service, which maps to one radio flow, only activates ifthere are enough free resources available.

A more concrete admission control mechanism in SL may be needed.

To enhance the admission control in SL, pre-emption mechanism may beneeded to drop low priority packet transmissions when high prioritypacket transmission is requested and there are not enough freeresources.

In one mode, e.g., Mode 3, gNB keep monitoring the resource usage of SLUEs. When channel is full, gNB can first stop some lowest prioritypacket transmissions and reserve those resources for newly arrived highpriority packets.

In another mode, e.g., Mode 4, a pre-emption signalling can be designed.UEs with high priority packets can pre-empt some resources used for lowpriority packets before starting its own transmission.

In the previous embodiments, the following may be obtained:

V2X service KPIs may be covered in 5GS QoS management for Uu.

LTE SL UEs may handle logical channel prioritization differentlydepending on their implementations.

A more concrete admission control mechanism in SL may be needed.

5GS QoS framework may be used for V2X services over Uu-interface.

A unified QoS handling rule, e.g., map a packet to a corresponding QoSflow, may be used for NR SL UEs.

In Mode3, gNB keep monitoring the resource usage of SL UEs. When channelis full, gNB can first stop some lowest priority packet transmissionsand reserve those resources for newly arrived high priority packets.

In Mode4, a pre-emption signalling can be designed. UEs with highpriority packets can pre-empt some resources used for low prioritypackets before starting its own transmission.

It should be noted that the aforesaid embodiments are illustrativeinstead of restricting, substitute embodiments may be designed by thoseskilled in the art without departing from the scope of the claimsenclosed. The wordings such as “include”, “including”, “comprise” and“comprising” do not exclude elements or steps which are present but notlisted in the description and the claims. It also shall be noted that asused herein and in the appended claims, the singular forms “a”, “an”,and “the” include plural referents unless the context clearly dictatesotherwise. Embodiments can be achieved by means of hardware includingseveral different elements or by means of a suitably programmedcomputer. In the unit claims that list several means, several ones amongthese means can be specifically embodied in the same hardware item. Theuse of such words as first, second, third does not represent any order,which can be simply explained as names.

1. A method for controlling sidelink (SL) Quality of Service (QoS), becharacterized by comprising the following steps carried out at a UserEquipment (UE): a) generating QoS requirement from characteristics forone or more packets to be transmitted via a sidelink; b) determiningbearer configuration corresponding to the QoS requirement; and c)performing SL transmission on the basis of the bearer configuration. 2.The method according to claim 1, wherein the UE is out of coverage of acellular network.
 3. The method according to claim 2, wherein a mappingrelationship between the QoS requirement and the bearer configuration isreceived from a network node and stored at the UE while the UE isin-coverage of the cellular network, or preconfigured at the UE.
 4. Themethod according to claim 1, wherein the characteristics are defined ina packet header complying with a protocol layer above Access Stratum(AS).
 5. The method according to claim 1, the step a) comprisingconverting the characteristics into corresponding QoS requirement on thebasis of a mapping relationship between the characteristics and the QoSrequirement.
 6. The method according to claim 5, the mappingrelationship between the characteristics and the QoS requirement isreceived from network node and stored at the UE while the UE isin-coverage of the cellular network, or preconfigured at the UE.
 7. Themethod according to claim 5, wherein one or more candidate mappingrelationships between the characteristics and the QoS requirement arereceived from the network node while the UE is in-coverage of thecellular network and stored at the UE, each of which corresponds to oneor more operational modes, and the operational mode comprises a RadioResource Control (RRC) connected mode, an RRC idle mode and Out ofcoverage (OoC) mode.
 8. The method according to claim 7, the mappingrelationship between the characteristics and the QoS requirement isselected from the one or more candidate mapping relationships dependingon which operational mode the UE operates in.
 9. The method according toclaim 3, wherein the mapping relationship between the QoS requirementand the bearer configuration is received via broadcast from the networknode.
 10. The method according to claim 7, wherein the candidate mappingrelationships between the characteristics and the QoS requirement arereceived via broadcast from the network node.
 11. The method accordingto claim 7, wherein at least two of the candidate mapping relationshipsare received from the network node while the UE is in-coverage of thecellular network and stored at the UE.
 12. A User Equipment (UE) withsidelink (SL) Quality of Service (QoS) controlling function becharacterized by comprising: a storage device configured to store acomputer program comprising computer instructions; and a processorcoupled to the storage device and configured to execute the computerinstructions to: a) generating QoS requirement from characteristics forone or more packets to be transmitted via a sidelink; b) determiningbearer configuration corresponding to the QoS requirement; and c)performing SL transmission on the basis of the bearer configuration. 13.The UE according to claim 12, wherein the UE is out of coverage of acellular network.
 14. The UE according to claim 13, wherein a mappingrelationship between the QoS requirement and the bearer configuration isreceived from a network node and stored at the UE while the UE isin-coverage of the cellular network, or preconfigured at the UE.
 15. TheUE according to claim 12, wherein the characteristics are defined in apacket header complying with a protocol layer above Access Stratum (AS).16. The UE according to claim 12, the step a) comprising converting thecharacteristics into corresponding QoS requirement on the basis of amapping relationship between the characteristics and the QoSrequirement.
 17. The UE according to claim 16, the mapping relationshipbetween the characteristics and the QoS requirement is received fromnetwork node and stored at the UE while the UE is in-coverage of thecellular network, or preconfigured at the UE.
 18. The UE according toclaim 16, wherein one or more candidate mapping relationships betweenthe characteristics and the QoS requirement are received from thenetwork node while the UE is in-coverage of the cellular network andstored at the UE, each of which corresponds to one or more operationalmodes, and the operational mode comprises a Radio Resource Control (RRC)connected mode, an RRC idle mode and Out of coverage (OoC) mode.
 19. TheUE according to claim 18, the mapping relationship between thecharacteristics and the QoS requirement is selected from the one or morecandidate mapping relationships depending on which operational mode theUE operates in.
 20. The UE according to claim 14, wherein the mappingrelationship between the QoS requirement and the bearer configuration isreceived via broadcast from the network node.
 21. The UE according toclaim 18, wherein the candidate mapping relationships between thecharacteristics and the QoS requirement are received via broadcast fromthe network node.
 22. The UE according to claim 18, wherein at least twoof the candidate mapping relationships are received from the networknode while the UE is in-coverage of the cellular network and stored atthe UE.
 23. A computer program product for controlling sidelink (SL)Quality of Service (QoS) in a cellular network, the computer programproduct comprising: a non-transitory computer readable medium storingprogram code configured for execution by processing circuitry of aterminal device to cause the processing circuitry to perform operations,the operations comprising: a) generating QoS requirement fromcharacteristics for one or more packets to be transmitted via asidelink; b) determining bearer configuration corresponding to the QoSrequirement; and c) performing SL transmission on the basis of thebearer configuration.